blueovalz

I've never seen that before. Without any other comments to dispute this, I would call Motorsport and return the bearings. The races should not ever be loose in the hub. Terry

Yeah, It's lean, but it can be adjusted at the AFM. The sliding resistor can be adjusted to allow the engine to run richer (and it does not take but a very small adjustment at all). Also, the return spring for the AFM can be tightened or loosened to affect the fuel curve (weaken the spring tension, and the mixture will richen because the computer thinks more air is going in being the flap is pushed further by the same amount of air). But this must be done very carefully too, 'cause the spring adjustment wheel only needs a few teeth of adjustment to make a big difference, and you do NOT want to let the spring wheel slip and "unspring" inself!! My concern here is once that cover is opened, moisture can start to be a problem. Be careful here.

My guess it's not the K&N. If it's FI, the AFM should still meter the air correctly, as would the SU set-up. Anyone else with a better comment? We need to know what year or type of fuel delivery your car has. Terry

Thinking about this I have come to this conclusion. The swept area of the rotor is less on the inner radius of the pad as opposed to the outter radius of the pad. With less area, heat is not dissipated as quickly. Which I quess is why bigger rotors run cooler than smaller rotors for the same energy conversion. Yeah Pete, I even installed new bushing kits with the grease and everything so that the floating would be effortless. Terry

Chris, If I remember correctly, the 280ZX rotors where too small not only for a simply bolt-on operation, but because they are simply smaller than the OEM Z rotors. The 300ZX rotors are a different story. The 4 lug 300ZX rotors will fit fine using the 280ZX calipers and 240Z hubs (the hubs with the half moon shaped cutouts on the circumference of the hub between the wheel studs, and with the 17mm thick flange). Later model hubs have flanges too thick to make this a simple swap because they set the rotor too far back to make the attachment of the caliper easy. If you take the rotors to a brake shop and have them remove about 1/8" off the circumference (radius, not diameter), then the calipers should bolt up nicely with only a small thin shim (I used a thick 12mm washer as the shim), and this is a close estimate so don't quote me on that dimension). Terry

Could you be using a thinner that is too "hot" also. I have had to use a less volatile thinner on hot days vs cooler days (just a suggestion)

The nearly horizontal spoilers take advantage of the low pressure behind the car, rather than create a high pressure situation over the top of it. I even remember a team using this in F1 with a real low rear wing. FIA out-lawed it and made a minimum height for the rear wing.

They can be made from fiberglass. The one's I built entailed some extra work vs making a plane ol' scoop or vent, but the look is great. We have had one member not long ago make his first fiberglass vents, and they appeared to turn out very nicely. Enthusiasm it key, then patience. Terry

Jeromio brought up an issue that was not replied to, and I wish to "confront" our technical best here: A single piston floating caliper has "x" square inches of area and moves "y" inches with each stroke of the master cylinder (squeezing against it's own frame). A 2 piston caliper (OEM Z caliper) as "2x" square inches of (assume both pistons are identical to the floater single piston) piston area, and each of these pistons only moves ".5y" inches per stroke of the master cylinder. Now add both sides (2 pistons) squeezing together and the total expansion of the pistons is now "y" inches, which is now the same squeeze distance as for the single floater per stroke. Thus I believe that in comparing single piston, vs multi-piston calipers, you compare the single piston size with only one side of the multi-piston calipers (or total of one side) size. Any engineers out there want to take this on and help us out? Oh yeah, No hub mods were necessary. Terry

Well, I know some of you ain't going to like this, but after reviewing several ideas on adaptors, I opted instead to lop off the ears that hold the OEM brakes, and then weld a braket I made out of 1/4" thick angle iron in their place. I put 3 additional photos http://albums.photopoint.com/j/AlbumIndex?u=1541023&a=11870007&f=0 of this process at the site showing an abbreviated process. I was leary of cutting up the strut, but it really went very smoothly. I have since done a series of repeated high speed stops and found no inconsistancy from first to the last (5 full acceleration pulls to 85mph/hard stops in a row with no cool down time in between pulls) using normal street semi-metallic pads. This is a great steet set-up, but a full racing set-up would still be preferable if I was to road race again. I'm headed to Disney tomorrow morning for a week, so you guys take care and be safe. Terry

Just a suggestion, on one of my first Z cars, I redrilled the mustache bar one inch higher for the diff cover studs, and then spaced the front mount higher also. This raising of the differential helped keep things more aligned on the half-shafts with my lowered suspension. The top of the differential was just touching the crossmember that the unibody uses over the diff after doing this. Terry

Originally, I just slipped these rotors over the front of the Z hub (had to reduce the O.D. of the wheel flange by about 1/8" to do it and then open up the rotor center hole too) and it could have worked very well this way. Plus the original 5 lug pattern is on a 4.5" pattern anyway, which will greatly simplify the rotor swap. Still, some work will be required for the caliper attachment. I only drive the car on the street now, and as such, have not put a full stress test on this system yet. I did ride the brakes real hard around the block a few times, but never felt any fading. I did realize something I had never thought about or knew before, but when I was doing a temp check of the rotors (IR temp) I noticed the inner portion of the rotor was much hotter (300 degrees vs 189 degrees) than the outer portion. Same thing on the rear brakes too. Just an observation. Terry

I had 245/45zr16 tires on my car with a stock rack, and the shorter arms. I had my buddy Charles Atlas parallel park for me, but once the car got any speed at all, the tight ratio was very nice. Terry

I hope I have not been miss-informed all this time but I thought all Z cars carried the same knuckle, and that the 10mm shorter ones were special competition stampings only. What's the real poop on this (being I paid $70 for the "competition arms" many years ago)? Are they really 510 arms? Terry

For those of you that have been waiting on baited breath, I have finally completed the Supra (12" rotor) brake conversion (replaced the '84 300ZX rotors/'83 280ZX calipers with the '87 Supra rotors and calipers). It envolved a little more work than I at first thought it would (can anybody here relate to that??????), and took an entire weekend to do both sides. The plus side is it cost $65 in salvage parts, new seals, and boots. Additional pictures can be seen at http://albums.photopoint.com/j/AlbumIndex?u=1541023&a=11870007&f=0 My next step is to get the SS braided lines back on the front, but will have to buy them again being the old ones were not long enough. Terry

I think an larger problem as perceived by the racers in the windor crank is the bearing speed instead of "slow reving"?? Terry

If you are writing about the rear brakes, yes, I think you chose the correct ones. I found the early brakes required a lot of offset in the rotor, and thus made the caliper mounting bracket hard to design. I instead used the later ones, which were easier (IMHO) to mount than the later ones (and lighter too). If you can get the turbo rear calipers, I believe the piston is slightly bigger than the N/A versions.

According to a book I once had access to for shaft rebuild specs: The 280ZX CV jointed shafts were 14-11/16" long (axle itself, w/o joints) for both sides. The extra length in the passenger side is between the splines and the inner CV joint (about 1/2"). FYI- the '84-'89 300ZX NA axles are 15-3/4" and 15-3/8" long and have the same spline pattern as the 280ZX axles, just a bit longer. Also, the tripod CV joint itself is the same part as the 280ZX (again, only the NA version). Terry

I'd say that was just about right. My old 780 has 69's up front and 73's in the rear. IMHO, the DP is more the problem than the jetting. In the VS, the secondaries open when the airflow is sufficiently high to warrant the additonal ventury size. On the DP, the secondaries open almost the same time as the primary, and thus creates the "gutless" feeling (loss of torque until RPMs come up high enough to utilize the already open secondaries). Try opening the throttle in a more sympathetic mode to RPM, and not all at once. Also consider using the 50cc accelerator pump instead of the OEM 25cc. This and even a slightly larger squirter (I think the OEM is a size 25) too. This may help. The center pivot floats are nice for my kind of driving, but I like the "automatic" opening of the VS, so the old 780 is the ideal carb (center pivot and VS) for me. I simply put a little weaker secondary spring to let the secondary open a little quick, and it works great. Also, if you are running unleaded, it's nearly impossible to read the plugs like you could with the old leaded gas, unless you run them for quite a while. I hope this helps. Terry

Update: I never do the the best thing first (except eat my cherry pie dessert first). When I adapted the '86 Supra 12" rotors onto the Z, I put them on the outside 'cause it worked good. I've now re-done the set-up to bolt onto the OEM rotor location behind the hub. I did this so that my options of a 4-puck caliper would be open. Anyway, At this time I have modified the strut for the attachment of the matching Supra caliper. I looked at one RX-7 4-puck caliper, but the pistons were only 1.375" in diameter (3" square for 2 pistons) and the Supra was a single 2.375" piston (4.4" square and same size as the 280ZX calipers). No contest on using the Supra instead of the RX7 calipers.

I removed and discarded this on both cars. No regret. Terry

To answer the balance question, a 5 hole disc pattern, in itself, is balanced because all five are equally spaced. The same can be said for a 4 hole pattern. To visualize the combination, do a thought experiment where you take both discs, and put them on the same axis of rotation. Does adding both discs together cause the assembly to be out of balance? No, because both balance independently. The new holes may look asymetric with the old holes, but a careful analysis of the angles, and using some simple trig, it can be found that mathematically, they are "symetrical". Terry

What I did to drill the the stud holes was put bolt a four holer onto the five holer rotor with a single bolt (both are 4.5" patterns). Using the hub holes, and the hat parts to aline the two rotors, I marked the new holes, punched, and drilled (in 3 stages to make sure the bits were staying true to the punch) it on a press. Basically I used the four holed rotor (Maxima) as a template. I personally feel I was very lucky to get no run-out. It was perfect. I hope I have the same luck with the other side. The studs I'm using are 1/2" and the new holes are 1/2" too. This makes for zero play when the rotor slips over the studs and hub center. There is no balance issue here either. The rotors are the same thickness as the 300zx, and they are vented. Once I can get a caliper solution figured out, then I'll be more optimistic about these rotors as an option for the fiscally prudent. The 300zx rotors work fine, but I'm at the limit of valve adjustment, and would like more braking up front. At this stage it's only an experiment. Terry

Messing around the salvage yard today and found 2 items that may be of interest to this site (my buddies) 1) I found a '95 Altima (not sure on the year or what model of Altima) that had the front rotors exactly identical to the older front Maxima rotors that I use on the rear of my Z (identical in every way) 2) Took a front rotor off a Supra (not current gen but the previous gen) that measured just under 12" X .8" (11.9"), and re-drilled the pattern to a four bolt pattern to match my Z. Slightly shaved the circumference of the Z hub, opened up the hub hole on the Supra caliper, slipped the rotor over the outside of the hub (just like current day cars do) and bolted it on. Took all of about 2 hours to do this correctly (with absolutely no run-out). Now I will find a way to match up a capliper, and I will have 1" larger rotors (than the 300ZX rotors currently on the front) on the front using salvage parts again. The ZX caliper I'm currently using could be modified to fit, but I'm going to try some other type. Anyway, the caliper needs only to be offset by about 5mm more toward the outside, and about 12mm radially, with this rotor than the ZX rotor provided for. And the wheel is now off-set about 6mm outward since the rotor fits between the hub and the wheel now. I'll find the exact year of the supra next week.

Well, I'll take a first un-educated stab at this. I've not used the Toyota set-up but I'm guessing that you've got the none ventilated calipers???(anybody else?). The ventilated calipers if they do indeed fit over the ZX rotors will be at least .9" wide (best guess)at the opening for the rotor. Terry